CD34 and myelodysplastic syndrome: Studies of low-risk MDS showed no increase in the frequency of immunophenotypically defined HSCs (Lin-CD34+CD38-CD90+CD45RA-) (Majeti et al., 2007; Pang et al., 2013), although multiple studies observed loss of granulocyte-macrophage progenitors (GMPs, Lin−CD34+CD38+CD123+CD45RA+) and relative expansion of common myeloid progenitors (CMPs, Lin−CD34+CD38+CD123+CD45RA−) in the bone marrow (BM) of low-risk MDS patients.